Blogs
High Pressure Roll Grinding for Copper Heap Leaching
Technology improvements in copper mining operations have been the key factor for increasing productivity. Beyond dump leaching, the industry will increasingly use various heap leach techniques in SX-EW operations in the coming years in order to optimize recovery and maintain low production costs. They include: Finer comminution followed by agglomeration. Finer comminution followed by coarse size separation for coarse heap
Effect of Water Chemistry on Flotation Performance
The two size reduction/froth flotation interactions described in this paper are strongly related to optimally using the inherent electrochemical surface rearrangements that occur on selected sulfide minerals, e. g. chalcopyrite, molybdenite, pentlandite, etc. Based on data generated in numerous fundamental studies, it is not surprising that utilizing the electrochemical transformations that occur with grinding could make a difference in downstream
Ceramic from Ilmenite & Zircon
The direct conversion of mineral concentrates into useful ceramic materials, without several intermediate processes, is of great interest to the materials community. Recently there has been increased interest in producing ceramic powders with very small sizes (in the order of nanometers) starting with mineral precursor. Thermal plasma processing of mineral concentrates may be used to obtain ceramic powders useful for
Convert Valve & Elbow to Equivalent Length of Straight Pipe
The 150mm (6″) elbows have a S value of 1.7 per Table II. This multiplied by 10 and 6″(150 mm) gives an equivalent length of straight pipe of 102′(31m).
Protection against Rockfall by Steel Wire Rope Safety Net Systems
Table of ContentsWire Rope Net Rockfall BarriersWere Rope Net Draping (Slope Protection) Wire Rope Net Rockfall Barriers A rockfall protection system with the appropriate strength characteristics and height can be designed. Wire rope net rockfall protection barriers of varying designs have been engineered with the proven ability to withstand impact kinetic energies ranging from 81 kJ (30 ft-tons) for the
Remove Micronized Magnetite from Coal
The micronized-magnetite coal cleaning technology is based on widely used conventional dense-medium cyclone applications, in that it utilizes a finely ground magnetite/water suspension as a separating medium for cleaning fine coal, by density, in a cyclone. However, the micronized-magnetite cleaning technology differs from conventional systems in several ways: It utilizes significantly finer magnetite (about 5 micron mean particle size), as
Selecting Centrifugal Slurry Pump Based
Making a sketch of the pump system, including dimensions, is very helpful in determining the static heads, friction heads, etc. After determining the top size of the solids and solid size distribution by the results of a screen analysis of the material, we can select the materials to be used in the construction of the pump. Having determined the flow rate
Gold Extraction in Carbonaceous Ore using Thiosulfate
Table of ContentsExperimental ProcedureCyanidation TestsScreening TestsOptimising Leaching TestsColumn Tests The U. S. Bureau of Mines has been investigating the application of thiosulfate to recover gold directly from low grade refractory carbonaceous ores for the past four years. Statistical experimental methods were used to determine the effects of various leaching parameters on both gold extraction and thiosulfate consumption. Seven variables were investigated,
Flotation Hydrodynamic
The Bureau of Mines conducted research on the flotation hydrodynamics of fine particle flotation to improve the flotation efficiency in our domestic minerals industry. The turbulent fluid velocity profile was measured in various flotation cells at different levels of dissipation energy. The importance of dissipation energy and bubble size within the flotation cells for the flotation response of a chalcopyrite
Effect of Turbulence in Fine Bubbles Flotation
Table of ContentsFlotation Model DevelopmentFroth FlotationConcentrate and Tailings AnalysesBubble Size MeasurementsVelocity MeasurementsPower MeasurementsResults and Discussion The U.S. Bureau of Mines examined the influence of turbulence on the fine bubble flotation of fine-sized (minus 10 micron) galena in order to improve flotation efficiency. Fine bubble flotation was carried out in a spinning-disk flotation cell and was compared to results obtained from
Redox Electrodes & Mineral Floatability
Table of ContentsBehavior of the black platinum electrodeComparative behavior of the gold and chalcopyrite electrodesComparative behavior of the chalcopyrite and galena electrodes Gold spiral electrodes were fabricated as a 3-turn coil of 10 cm long wires of 0.5 mm diameter. Following the hypothesis that a black platinum electrode follows more closely the solution potential than the mineral potential due to
Slurry Volume Hold-Up of Overflow Ball Mills
Figure 1 shows the head-on view of a typical overflow discharge mill including the definition of symbols and specific mill volumes to be used. In this discussion it is assumed that the overflow discharge mill being operated at steady-state will demonstrate a reservoir effect, that is that the Volume 1 of Figure 1 will be fully occupied by the mill
Carlin Trend Geology
Table of ContentsStratigraphyIntrusive RocksStructureAlteration Stratigraphy The stratigraphic sequence in the Carlin Trend Geological area is Lower Paleozoic marine sediments and Late Tertiary tuffaceous sediments. The Lower Paleozoic sediments consist of the Siluro-Devonian Roberts Mountains Formation, the Devonian Popovich Formation and the locally named Rodeo Creek Formation. The Rodeo Creek Formation had previously been described in the mine area as the
Jarosite Production
Jarosite Production: The roast-leach-electrowin process for zinc production involves roasting zinc sulphide concentrate to produce calcine containing zinc oxide. Zinc concentrate roasted at Risdon typically contains about 11% iron, which is predominantly converted to zinc ferrite (ZnFe2O4) during the roasting operation. When the calcine is leached under weak acid conditions (pH ≤ 2) only the zinc oxide fraction of the calcine is
No Conditioning Carbonate Flotation
Table of ContentsCollector ScreeningOptimization of Collector Dose, pH and Pulp SolidsEffect of Collector ConditioningEffect of Frother DosageEffect of Type of pH Modifier Tests to study the effect of collectors and pH were randomly conducted on the phosphate matrix, using a 2k full factorial design for collector screening and process optimization. Star points needed to estimate non-linear factor responses were included
Calcium Montmorillonite Flocculation
The flocculation process involving fine particles and organic polymers can be depicted by the following sequence: adsorption of the polymeric species on particles, conformational changes in the adsorbed polymer molecules, and collisions between particles to form flocs through bridging. Flocculation is the result of mixing the polymer with the particle slurry in some device, e.g., tank equipped with stirrer, static
Optimum Carbon Loading CIP Circuit
Table of ContentsLoading of CarbonAverage Carbon Loading FactorCalculation of Carbon Loading Factor Figure 1 simplifies a CIP circuit, implied are the transfer and screening mechanisms. Gold/silver are dissolved, activated charcoal (carbon) is moved countercurrently to the flow of ore adsorbing gold/silver. The charcoal is removed from the circuit, stripped of its metal content, regenerated and then returned to the circuit
Smectite Ceramics
Smectite is the name for a group of sodium, calcium, magnesium, iron, lithium aluminun silicates which include the minerals sodium montmorillorite, calcium montmorillonite, saponite, nontronite, and hectorite. The rock in which these smectite minerals are usually dominant is bentonite. The theoretical formula without considering lattice substitutions is (OH4Al4Si8O20 · N H2O (interlayer), and the theoretical composition without the interlayer material is
Diatomite Deposit Formation
Worldwide, diatomites occur within Tertiary to Recent lacustrine and marine sediment facies (see Table 1). Geologically, the oldest marine and lacustrine diatoms predate the effusive blooms of the post Oligocene depositional period, and are respectively found within Cretaceous and late Eocene sediments. In the U.S., marine species are found in rocks as old as the California’s Cretaceous Moreno Shales. The
Dredge Mining
The dredge selected for the project was the Para. It is purportedly the largest discountable dredge in the world. Two weeks after its arrival at the project site by rail, the Para was ready to operate. The Para has a 0.75 m (29½ inch) suction and a 0.70 m (27½ inch) discharge. It has 600 horsepower to the cutter, and
Thickener Performance Optimization
The results of this study can be shown as counter plots. Due to the variety of experimental runs and generation of numerous plots it would be beyond the limits of this paper to discuss all of the cases. Therefore, the discussion will be based on the plots given in Ghalambor (1980), and only a few will be presented here (figures
Install Jig in Grinding Circuit to Recover Gold
The project consisted of installing one jig and one belt strake on each of the four grinding sections. A portion of the circulating load in the ball mill circuit is pumped to the jig. The jig is placed over the top of the belt strake. The concentrate from the jig flows onto the belt strake. The tails from the jig
CIL Tailings Gold Flotation
Table of ContentsColumn FlotationEffect of Collector AdditionEffect of pH and Redox PotentialAutoclave-CIL A preliminary series of laboratory flotation tests was performed to determine the nature of the unleached gold values of the CIL tailings. The gold in the Mercur mining district has been identified historically as being associated with sulfide and carbonaceous minerals in addition to a percentage occurring as
GORE-TEX membrane filter cloth
Table of ContentsGORE Back-Pulse FiltrationPrecoat Replacement in Filtration of Merrill Crowe Precipitates GORE-TEX membrane filter cloths for liquid filtration consist of expanded polytetrafluoroethylene (PTFE) membranes bonded to a variety of felts and other fabrics (including fabric woven of PTFE fiber). The PTFE membrane/PTFE fabric filter cloth is inert to practically all chemicals and can be used at temperatures up to